BOSTON -- Giving police chiefs discretion to decide who should have a license to carry a shotgun or rifle is crucial to prevent gun violence, domestic violence murders and suicides, police officials and other activists said at a State House rally Tuesday.

Police chiefs know the dynamics in households where there is a history of violence or mental health problems that might not show up in background checks, Boston Police Commissioner William Evans said during the rally at the Grand Staircase.

Senate lawmakers last week voted 28 to 10 to eliminate a provision in gun violence prevention legislation that would give discretion to police chiefs issuing firearms licenses for rifles and shotguns. Chiefs already have such discretion in issuing handgun licenses.

“This has been a constant problem that our legal gun owners and sportsmen have had to deal with, we have had local appointing authorities that - some are very good about this but some also have abused the authority and for no reason have determined people unsuitable to possess or to get a license to carry,” Sen. Michael Moore (D-Millbury) said last week, arguing against additional discretion under the so-called suitability clause and noting the bill includes new powers to deny FID cards to a “prohibited person.”

Flanked by more than a dozen police officials, including former Boston Police Commissioner Ed Davis, Evans said he was “really disappointed in the Senate.” He said, “No one knows more than us how important it is to control guns that go in the hands of people who aren’t suitable to have the handguns.”

The House version of the anti-gun violence bill included discretion for police when issuing rifle and shotgun licenses. Law enforcement officials and advocates are pushing to include discretion for chiefs in rifle and shotgun applications in the final version of the legislation before sending it to Gov. Deval Patrick’s desk - a conference committee will likely make final choices about the bills details in the coming days.

“What the Senate chose to do is placate the NRA instead of supporting law enforcement,” John Rosenthal, founder of Stop Handgun Violence, said at the rally.

Senators stripped the bill of the “cornerstones of the legislation,” when they removed the discretion for police chiefs, Rosenthal said.

Page 2 of 4 - According to Rosenthal, there have been 74 school shootings since the Sandy Hook Elementary School massacre in December 2012, and in almost all of them a shotgun was used. The school shootings in Newtown, Conn. where 20 school children and six adult staff were murdered spurred lawmakers across the nation, including in Massachusetts, to reexamine gun laws.

While chiefs have discretion when deciding licenses to carry a handgun, police say under current law and in the legislation passed by the Senate, their hands would be tied when issuing a firearms identification card. They would have no way to prevent someone from buying a shotgun or rifle who they know has a history of violence or emotional instability.

A prominent gun rights activist argued police chiefs have abused their power to decide who is suitable for gun licenses.

“And in many cities and towns across Massachusetts, it’s that abuse that has put gun owners backs against the wall,” said Jim Wallace, president of the Massachusetts Gun Owners Action League (GOAL). “And basically the position is don’t even think about expanding an authority you’ve abused at least until you’ve reined it in. And right now there isn’t anything that shows us that it’s going to be reined in any time soon.”

Wellesley Police Chief Terry Cunningham, who Rosenthal described as a “rising star nationally” in law enforcement, said current law states the police chief “shall” issue a FID card if the person is not disqualified by statute.

While police chiefs have the ability to deny a handgun license based on clear factors, such as they are likely to pose a risk to themselves or others, propensity for violence, substance abuse, or evidence of emotional instability, the individual can apply for an FID card the next day, and police chiefs are “forced” to issue it, Cunningham said.

“Are people really going to be any less dead if they’re killed with a rifle or shotgun than a handgun,” said Cunningham, who is in line to become president of the International Association of Chiefs of Police.

“Who better to determine if an individual in the community has a propensity for violence, as [Oak Bluffs Police] Chief [Erik] Blake said, or has a history of domestic abuse even if the individual has never been arrested and no restraining order has been issued except the chief of police,” he added.

Wallace, from GOAL, questioned whether it was a “real problem, or a perceived problem” that police officials were talking about, and wanted to know what percentage of people who have been issued FID cards have committed violent crimes.

“So far we haven’t seen any evidence of it,” Wallace, who watched the event from a bench nearby, told the News Service.

Page 3 of 4 - Wallace called the overall legislation “phenomenal” because it covers aspects of mental health, school safety, crime, as well as addresses the National Instant Criminal Background Check System (NICS), a federal database used for determining eligibility to purchase a firearm in the United States. Massachusetts is one of seven states that do not provide mental health commitment status information to NICS.

“We’ve got an opportunity here to pass a once in a lifetime piece of legislation and it goes to conference committee and dies because of one paragraph, that’s on their heads not on ours,” Wallace said.

One police chief called it “ludicrous” that he could deny someone a license to carry based on knowledge of the person’s domestic violence history or mental health, but if they apply for a license to buy a shotgun or rifle, he has no ability to deny them.

“There is no difference between a shotgun and a handgun, they are both devastating weapons in the hands of the wrong people,” said Blake, president of the Massachusetts Chiefs of Police Association.

He continued, “It is not about being capricious or arbitrary and taking away people’s rights. It is about safety in our community and knowing who has a gun in our community.”

Anyone denied a license to carry a handgun has the right to appeal the decision before a district court judge, and explain why they think the police chief is wrong. Blake said police should have the same right to go before a judge to explain why they denied the license.

Davis told a story of an incident about a year before he left the commissioner’s role, where a man who had killed an 80-year-old man held police at bay using a shotgun. Davis said he had issued the man an FID card, based on the law. He said it is important for police to have discretionary powers.

Davis said he has not spoken with Senate leaders yet about the bill, but he is confident a compromise on the discretion language can be worked out. “And I am certain when the governor signs this bill, Massachusetts is going to be a safer place,” Davis said.

On Tuesday, House lawmakers appointed a conference committee to work out the differences with the Senate, naming Reps. Ronald Mariano (D-Quincy), Garrett Bradley (D-Hingham) and George Peterson (R-Grafton).

Rep. Ellen Story, an Amherst Democrat and member of House Speaker Robert DeLeo’s leadership team, said she was both disappointed and surprised by the Senate vote.

“To see that the Senate took out one of the most important provisions was stunning to me,” Story told the News Service after attending the police chiefs’ rally. “I don’t understand quite what happened in the Senate process but I am hopeful and I am confident we will be able to come to some kind of compromise so that the bill can pass in its stronger form and be effective in preventing gun violence.”

Page 4 of 4 - Asked whether House negotiators would insist on discretion for police chiefs when issuing rifle licenses, Story said, “The House will hope that there is something about giving police chiefs the discretion to deny long guns to people who should not have them. Whether the language is slightly different doesn’t matter but the idea of this has to be included.”

The two Democratic candidates for attorney general, Warren Tolman and Maura Healey, attended the rally, both saying discretion for police chiefs is necessary.

“There are instances where people get long guns that wouldn’t be otherwise eligible for the handguns, and they have committed crimes with them,” Tolman said after the event.

“The public and the people are crying out for this kind of reform. I think you heard the chief articulate just how common sensicle this is and why it’s so desperately needed,” Healey said.

Tolman’s campaign on Monday was critical of Healey for not directly commenting on the Senate’s vote on Sen. Michael Moore amendment, but Healey said her position has not changed since she released her own plan earlier in the campaign to address gun violence.

“One of the things I talked about early on in my plan was suitability and the very measure that is now being debated today so I’ve been always on board with that. It was part of my plan. I was disappointed that the Senate took it out and I sure hope that after today and people’s action in speaking out that we see it back in. Nobody’s more committed to this,” Healey said.

Tolman, a former state senator, did not want to speculate on why the Senate removed the provision. He pointed out the two candidates disagree on requiring smart gun technology – incorporating mechanisms in guns such as fingerprint identification that could prevent unauthorized people from firing a weapon. While Healey supports legislation for smart gun technology, she has said she does not believe, as Tolman does, the attorney general’s office has the power to mandate the technology on guns sold in Massachusetts.